1. Field of the Invention
This invention relates to connectors, and, more particularly, to connector apparatus for flexible electrical conduit.
2. Description of the Prior Art
Flexible electrical conduit is required as an outer sheath for many types of electrical wiring within structures, such as between walls. The flexible conduit is formed of a continuous strip of steel which includes a pair of oppositely extending corrugations adjacent each other. The corrugations are not of equal size, and one corrugation is substantially larger than the other one. The steel strip is wrapped around itself in a helical fashion such that the large corrugation overlaps the adjacent smaller corrugation. In this manner a helical or spiral corrugation extends throughout the length of the conduit thus formed. The resulting conduit is flexible such that it will bend longitudinally, but the corrugation will not yield radially inwardly nor radially outwardly except under a substantial force. In other words, the flexible conduit is not deformable radially, but is bendable along its longitudinal axis to enable it to form a sheath of substantially continuous or constant diameter as it bends as required. Electrical conductors or wires extending through the flexible conduit are protected from damage from pinching, or the like, due to the relative rigidity of the walls of the flexible conduit.
The flexible conduit has the beneficial characteristics of strength and flexibility, but has a substantial disadvantage in that it is difficult, by prior art methods, to electrically connect the flexible conduit to a junction box at the termination of the conduit. The contemporary electrical codes require the grounding of the junction boxes at the termination of the conduit and the primary way of achieving such grounding, as approved by the Underwriters Laboratory, is simply to run a bare, third wire through the conduit with the insulated conductors and clamping the bare wire to the junction boxes. This obviously has its difficulties or its disadvantages due to the extra costs involved in terms of both labor and extra cable or electrical conductor required.